I. Technical Field
The present disclosure generally relates to the field of computing and to techniques for providing challenge-response animation and testing targeted for a human. More particularly, and without limitation, the present disclosure relates to computerized systems and methods for randomizing and animating images on a display for purposes of ensuring a response is not generated by a computer impersonating a human. By way of example, the randomized and animated images can be used to control access to data or computerized services, as well as to prevent malicious computers from hacking or accessing protected content.
II. Background
Controlling access to data or computerized services can be implemented in many different ways. For example, data can be protected using techniques such as user names and passwords, hidden files, and/or attributes that prevent certain data from being read or modified. However, such techniques are insufficient when the goal is preventing automated access to data or computerized services while sharing the same freely with human users. For example, certain web pages may need to be protected from web robots or bots, while still making these web pages generally available to the public.
Completely automated public Turing tests to tell computers and humans apart (“CAPTCHA”) techniques have been implemented. In general, a CAPTCHA is a challenge-response test that requires a human user to correctly identify and type displayed letters and/or digits in order to proceed with accessing data or computerized services. To prevent a web bot or malicious computer from automatically interpreting and entering the displayed letters and/or digits, the display may be distorted, warped, or combined with graphics (e.g., adding an angled or curved line).
Web bots typically incorporate optical character recognition (“OCR”) techniques to overcome basic CAPTCHA content. To make it more difficult for bats and computers to correctly respond to a CAPTCHA challenge, increased distortion or warping can be used to defeat the automated optical character recognition. Such techniques, however, can make it much more difficult or impossible for human users to correctly identify the displayed letters and/or digits and, thus, defeat the usefulness of the CAPTCHA.
Conventional CAPTCHA techniques are also susceptible to other methods of automated access or completing a registration process. One technique is to use a “botnet” or a collection of web bots to “scrape” CAPTCHA images and send them to human users, who then solve the CAPTCHA for the web bot. The individual web bats can then simply proceed to access the protected content without further human intervention.
In view of the foregoing, there is a need for improved challenge-response techniques that are able to protect data or computerized services from web bots or computers capable of optical character recognition. Further, improved systems and methods are needed that are resistant to techniques that use humans to solve, for example, “scraped” CAPTCHA images. Moreover, improved systems and methods are needed that overcome the drawbacks of conventional CAPTCHA images, while at the same time provide displayed letters and/or digits that can easily be identified by a human user.